thank you-
it is not a big matter, because if i need to use the "pure" phase
comparator out i can adjust the 50k pot so it's not filtering the
signal. in any case, i'd be curious what the real cause is and how
you'd "solve" the problem.
--tom

> I will check why the LP setting influences the PC output. I assume

that the

> PC outputs of the PLL circuit have a higher impendance (probably

some kOhm)

> than expected. As the LP is a very simple RC type (1k fixed

resistor + 50k

> potentiometer + 10u capacitor) it may load the PC output as in the

highest

> frequency setting it loads the PC output with 1k against 10u and may
> consequently affect even the PC output. An additional buffer in the

PC

> output (between PC output and LP input) would decouple the PC

output from

> the LP. I will see if I can find a simple solution. Another

solution would

> be to disconnect the PC output from the LP input as soon as a plug

is

> inserted into the PC out socket by using the switching contact of

the PC

> output socket.
>
> Best wishes
> Dieter Doepfer

> >